Aluminum-containing coatings are produced over rotor blades, nozzle vanes, combustor parts, and other turbomachine components for protection from rapid degradation within the high temperature, chemically-harsh turbomachine environment. Aluminide coatings, for example, are often formed over turbomachine components to minimize material loss resulting from oxidation and corrosion. To produce an aluminide (or other aluminum-containing) coating, at least one aluminum-containing layer is deposited onto the surfaces of the turbomachine component over which the aluminide coating is desirably formed. The aluminum-containing layer may be composed of relatively pure aluminum or may instead contain other constituents, such as chromium or platinum, co-deposited with aluminum. In conjunction with or after deposition of the aluminum-containing layer, a diffusion process is carried-out to form aluminides with the superalloy material of the turbomachine component. Over the operational lifespan of the turbomachine component, the aluminide coating gradually recedes or wears away; however, the recession rate of the aluminide coating is significantly less than the rate at which the underlying turbomachine component would otherwise oxidize, corrode, and recede if left uncoated. Thus, through the formation of such a high temperature aluminide coating, the operational lifespan of the turbomachine component can be extended.
Conventional processes for depositing aluminum-containing layers over turbomachine components include pack cementation and Chemical Vapor Deposition (CVD). Such deposition processes are associated with a number of drawbacks, which may include undesirably high processing costs, cumbersome high temperature masking requirements, and the general inability to deposit aluminum-containing layers over non-planar, geometrically-complex surfaces in a predictable and controlled manner. Recently, ionic liquid bath plating processes have been introduced, which provide a relatively low cost approach for depositing aluminum-containing layers onto metallic workpieces. As a further advantage, ionic liquid bath plating processes are carried-out under low temperature conditions at which high temperature masking is unneeded. While such advantages are significant, ionic liquid bath plating processes remain limited in certain respects. For example, as conventionally performed, ionic liquid bath plating processes are typically incapable of depositing an aluminum-containing layer over the non-planar surfaces of a metallic workpiece, such as the aerodynamically-streamed surfaces of a turbomachine component, in a consistent and controlled manner without the usage of relatively complex plating set-ups; e.g., plating set-ups including relatively large anode pin arrays, auxiliary anodes, multiple power sources, and the like.
It is thus desirable to provide ionic liquid bath plating process enabling the deposition of aluminum-containing layers over contoured workpiece surfaces, such as the aerodynamically-streamlined surfaces of turbomachine components, in a controlled and cost-effective effective manner. For reasons explained more fully below, it would also be desirable to provide ionic liquid bath plating processes enabling the deposition of aluminum-containing layers having three dimensionally-tailored thickness distributions. Finally, it would be desirable to provide embodiments of turbomachine components having three dimensionally-tailored, aluminum-containing coatings produced, at least in part, from aluminum-containing layers. Other desirable features and characteristics of embodiments of the present invention will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying drawings and the foregoing Background.